Properties of Diphyl THT
General chemical and physical properties
Diphyl THT is a high‑performance, heatresistant synthetic heat transfer fluid for use in the liquid phase in closed heat transfer systems.
Diphyl THT is a
clear, colourless to pale yellow liquid. It is odourless and,
because of its polyphenyl structure (chemically: partly hydrogenated
terphenyls),
has extremely high thermal stability with a long operating life.
Because of its high boiling range, Diphyl THT can be used in pressureless systems over the entire operating range.
The high purity
of Diphyl THT, i.e. absence of e.g. chlorine and sulphur con-taminants, ensures that there is no corrosion whatsoever of the metals normally
employed for heat transfer equipment.
The application
range of Diphyl THT is between O °C and 345 °C.
The film temperature should not significantly exceed the limit of 370 °C,
nor exceed it for very long.
Diphyl THT - specification and characteristic data
Specification
Total THT content
(%) min. 99,5
Water (mg/kg) max. 100
Specification values are subject to constant monitoring
Characteristic data
Composition partially
hydrogenated terphenyl
Appearance clear, pale
yellow liquid
Range of application (°C) 0-345
Max. Film temperature (°C) approx. 370
Initial boiling point (°C) approx. 352
Density (g/cm3), 20°C approx.
1.004
Kin. viscosity (mm2/s)
0 °C approx.
903
20 °C approx.
101
40 °C approx.
27
60 °C approx.
5.8
100 °C approx.
3.6
Pourpoint (°C) approx. - 33
Refractive index (nD20)
approx. 1.5740
Neutralization number (mgKOH/g) approx. 0.01
Flash point (°C) - approx. 190
Fire point (°C) approx. 205
Autoignition temperature (°C)- approx. 380
Temperature class VDE 0171 T2
Thermal conductivity (W/m . K), 20 °C approx. 0.11
Specific heat (kJ/kg . K), 20 °C approx.
1.54
Coefficient of thermal expansion, (K-1), 300 °C approx. 8.4 .
10-4
Characteristic data provide further information about the product.
And are not subject to constant monitoring.